For diabetic patients, fasting during Ramadan, the ninth month of the Islamic calendar, can cause wide fluctuations in blood sugar levels, posing a medical challenge for patients and physicians and increasing the risk of acute metabolic complications including hypoglycemia, hyperglycemia, diabetic ketoacidosis, dehydration, and thrombosis. Proper patient education, risk stratification, and modification of antidiabetic medications can reduce the risk of complications.